If you cannot accept Calvinism, attacking Calvin seems to be the easiest to do. Why not focus on TULIP and see that this is the only biblically sound doctrine? Rejecting any one point is rejecting the completeness of scripture.
Jesus was quite clear that the evaluation of prophets should be based on the fruit of their life. Calvin’s feelings about killing heretics and people who disagree with him about killing heretics is a direct reflection on his theology.
The TULIP is a very tightly consistent theology with itself, but is inconsistent with much of scripture. I’m sure you’ve seen the passages, but you simply choose to explain them differently. It is the seeming inconsistencies of scripture that I appreciate and I simply wait in faith until I see face to face.
It seems the place to begin with TULIP is whether God offers his atonement to everyone or to a limited elect only. Unless it’s bent and twisted, there is much scripture clearly states that God’s desire is that all would be saved and that his salvation is offered to to all. There are hints of truth that are in each part of the TULIP but only when they are held in tension with the other parts of scripture.
Total depravity - yet created good
Unconditional election - yet called to choose
Limited atonement in the end - yet all are given the opportunity to choose Christ
Irresistible grace - which hints toward a hope that all will eventually be redeemed.
Perseverance of the saints - no, we can fall away. It takes some real twisting of some scripture to say we can’t.
Tight consistency in theology is not inherent to Christianity or Judaism, it is an impulse borrowed from the Greeks and Islam. My experience has been that the preachers that have all the details of their theology worked out tend to be the least charitable toward others, not matter what religion they claim to follow.